Immunizations
JFK pediatric core curriculum
MGH Center for Global Health
Pediatric Global Health Leadership Fellowship
Credits:
Brett Nelson, MD, MPH
Discussion outline
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Success of immunizations
Still significant room for improvement
Immunization schedules
Administration of vaccines
Contraindications
Specific vaccines
Immunizations save lives
Globally,
immunizations save
the lives of
approximately 3
million people each
year
Vaccines are safe
• Immunization is among safest
of modern medical
interventions
• Vaccines are easier and safer
to administer than ever before
• Being immunized is much
safer than risking infection
and disease
Immunization can save money
• Immunization is
one of the most
cost-effective
health
interventions
• Investing in
vaccines
SAVES more
money than it
costs
Immunization can protect the
unprotected
• When immunization
coverage is high, it can
prevent viruses and
bacteria from circulating
• The more children in a
community that are fully
immunized, the safer
everyone is
• Unfortunately, ….
34 million children are
not fully immunized
2.3 million still die each year
Diseases reappear when
coverage drops
Immunization coverage in Liberia
Significant success over the last decade
http://www.who.int/vaccines/globalsummary/immunization/countryprofileresult.cfm
Liberia immunization schedule
(coming soon?)
http://www.who.int/vaccines/globalsummary/immunization/ScheduleSelect.cfm
WHO EPI schedule by age
WHO Pocket Book of Hospital Care for Children. Page 297.
Administering vaccines
• Most doses for children are
0.5ml IM or SC
• Sites of IM/SC administration:
– <18months: anterolateral thigh
– Toddlers: anterolateral thigh or
deltoid
– Older children: deltoid
• Give IM:
– DTP, Hib, Hep B
• Give SC:
– Measles, yellow fever
Contraindications to immunizations
• Important to immunize all children, including
those sick and malnourished, unless there are
contraindications
• Common side effects to vaccines:
– Pain, local swelling, fever, fussiness, drowsiness,
vomiting, anorexia
• General contraindications to any vaccine:
– History of anaphylaxis to that vaccine or vaccine
component
– Current moderate or severe illness regardless of fever
Specific contraindications
• BCG and yellow fever
– Do not give BCG or yellow fever vaccines to child with symptomatic
HIV/AIDS
– But do give BCG and yellow fever vaccines to a child with asymptomatic
HIV infection
• DPT
– Do not give DPT-2 or -3 to child who had seizures or shock within 3
days of previous DPT dose (possible encephalopathy to pertussis
component)*
– Do not give DPT to child with poorly controlled seizures or active CNS
disease*
*(If available, can give DT vaccine with no pertussis component)
• OPV
– A child with diarrhea who is due for OPV should be given OPV
– However, this dose should not be counted in schedule
– Make note on child’s immunization record that it coincided with diarrhea,
so that health worker will know this and give an extra dose
BCG vaccine
•
TB currently accounts for more deaths than any other infectious disease
– Almost 3 million people a year, including nearly 300 000 children
– Over 50 million people infected with drug-resistant strains
•
BCG (Bacille Calmette-Guérin) is a live vaccine
– Administered intradermally (produces small raised "bleb“) at birth
•
Most widely used of all EPI vaccines
– In 1997, almost 90% of the world’s children were immunized with BCG
– 50-80% effective against most serious forms of childhood TB: miliary TB and TB
meningitis
– Offers some protection against leprosy
– Uncertain protection against adult forms of TB
•
WHO recommendations:
– In countries with high incidence of TB, immunize infants and children <5 years
with single dose of BCG
– Where definable high-risk population, countries may limit BCG to infants (such is
schedule in Liberia)
– Booster doses not recommended
Oral polio vaccine
• 2 kinds of polio vaccine
– Inactivated injectable polio vaccine (IPV) originally developed in 1955 by
Dr Jonas Salk
– Live attenuated oral polio vaccine (OPV) developed by Dr Albert Sabin
in 1961
– Both highly effective against all 3 types of poliovirus
• OPV is vaccine of choice for eradication of poliomyelitis
– 5x less expensive
– Easier to administer (PO vs IM)
– Most importantly, induces immunity in gut, where poliovirus multiplies
• IPV provides individual protection against polio paralysis but not capable of
preventing spread of wild poliovirus since induces very low immunity in gut
• WHO recommendations:
– 4 doses of OPV before first birthday (birth, 6, 10, 14 weeks)
– However, supplementary doses are given during National Immunization
Days to achieve eradication
DTP vaccine
• Combination vaccine against diphtheria, tetanus, and
pertussis (whooping cough)
• Given IM in 3 doses, at least 4 weeks apart (6, 10, 14
weeks)
• Variations:
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DT (full diphtheria and tetanus toxoid, but no pertussis)
Td (tetanus toxoid and reduced diphtheria; for adults)
TT (tetanus toxoid alone; for women of childbearing age)
Some countries have substituted acellular pertussis vaccine (aP)
for whole-cell pertussis component (wP)
– Some manufacturers have added Hepatitis B and/or Hib vaccine
to simplify administration and reduce costs
Hepatitis B vaccine
• >2 billion people alive today have been infected with hepatitis B
virus
– Of these, ~350 million remain chronically infected, can transmit the
infection, and can develop liver cirrhosis or cancer
– Every year, ~4 million acute clinical cases of hepatitis B and ~1 million
deaths
– Primary liver cancer caused by hepatitis B is now one of principal
causes of cancer death in many parts of Africa, Asia, and Pacific Basin
• Globally, child-to-child and mother-to-child transmission accounts for
majority of infections and carriers
– Also transmitted through sexual contact, unsterile needles or other
medical equipment, infected blood products, skin piercing
• Vaccine given IM in 3 doses, at least 4 weeks apart (6, 10, 14
weeks)
– Same schedule as DTP
• Although vaccine price has fallen, still more expensive than
traditional EPI vaccines -- many developing countries cannot afford
Hib vaccine
• Haemophilus influenzae type b (Hib) causes serious
bacterial infections
– Meningitis, pneumonia, and infections of blood, bones, and joints
(does not cause influenza)
– ~3 million serious illnesses and 386,000 deaths each year
– Most common between 4-18 months, but can occur in older
children
– Leaves 15-35% of survivors with permanent disabilities such as
mental retardation or deafness
• Vaccine available alone or combined with DTP or
hepatitis B (e.g. DTwPHibHep)
• WHO recommendations:
– 3 doses given IM at 6, 10, and 14 weeks ("where resources permit its
use and burden of disease is established“)
Yellow fever vaccine
• Yellow fever is untreatable, viral, hemorrhagic disease, transmitted
by mosquitoes, with high fatality rate (30,000 deaths/year)
• Yellow fever and measles vaccines are similar in nature and both
administered SC at 9 months
• WHO recommendations:
– 1 dose SC at 9 months for all infants
in ~45 countries comprising yellow
fever belt of Africa and South
America
– Re-immunization not indicated as
vaccine thought to produce virtually
life-long immunity
– (However, travelers to these
countries require vaccine every 10
years)
Measles vaccine
• Among vaccine-preventable diseases, measles remains the leading
cause of child deaths
– Nearly 1 million deaths every year, mainly in developing countries
– However, even eradication efforts in developed countries like the U.S.
have not been successful
• Live attenuated vaccine
• WHO recommendations:
– Like yellow fever, 1 dose given SC at 9 months
– Where >15% of measles cases and deaths occur before 9 months of
age, give extra dose of measles vaccine at 6 months, then routine dose
at 9 months
– Also give extra measles dose for infants at high risk: infants in refugee
camps, admitted to hospitals, HIV-positive, and affected by disasters or
measles outbreaks
– Oral Vitamin A drops often given at same time as measles vaccine to
prevent blindness and reduce measles mortality
Conclusions and implications
• Vaccines are among safest and most effective medical
interventions
• Ensure up-to-date immunization status
– Check records with each patient encounter
– Give missing vaccines to hospitalized patients prior to discharge
• One last review:
References
• Children’s Vaccine Program, Global Alliance of Vaccines and
Immunizations. www.childrensvaccine.org
• Immunization Action Coalition. http://immunize.org/catg.d/p2020.pdf
• WHO. By-country vaccine schedule.
www.who.int/vaccines/globalsummary/immunization/ScheduleSelect
.cfm
• WHO. Expanded programme on immunization – overview.
http://wbln0018.worldbank.org/HDNet/HDdocs.nsf/0/6b9066a4c849
16ec8525676a004d6c5e?OpenDocument
• WHO. Liberia reported immunization coverage.
http://www.who.int/vaccines/globalsummary/immunization/countrypr
ofileresult.cfm
• WHO. Pocket Book of Hospital Care for Children.
http://www.who.int/child_adolescent_health/documents/9241546700
/en/index.html